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  • 1
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 14 (1967), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. In the nearly mature macrogametes of Eimeria auburnensis, the cell membrane is a unit membrane, with underlying and overlying osmiophilic layers usually present. Cup-shaped micropores were occasionally seen. Smaller, V-shaped invaginations were also found in considerable numbers at the surface. At the deepest point, these invaginations were bounded only by a unit membrane. Immediately adjacent to this point, vesicles with homogenous electron-pale contents bounded by a similar unit membrane, were frequently seen. Pinocytosis evidently occurs at the site of these invaginations. Numerous folds of the host cell membrane bordering the vacuole in which the parasite lay extended about 0.1–0.7 μ into the vacuole. These “intravacuolar folds” varied in depth and number in different specimens. In some, the majority of folds had apparently become disconnected from the host cell membrane. A highly developed smooth endoplasmic reticulum occurred in the adjacent host cell cytoplasm. The intravacuolar folds may assist in transfer of nutrients, including membrane material, from the host cell to the parasite. The evidence indicates that in this species of Eimeria nutrients are taken into the parasite primarily as fluids by pinocytosis and possibly other processes.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 31 (1984), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: Two strains of Trichomonas vaginalis, JH162A, with low pathogenicity, and Balt 44, with high pathogenicity, as well as one highly pathogenic strain, KV-1, of Tritrichomonas foetus were studied by freeze-fracture electron microscopy.The protoplasmic faces (PFs) of the cell membranes of all three strains of both species had similar numbers of intramembranous particles (IMPs); however, the particles in the external faces (EFs) of these membranes were least abundant in Trichomonas vaginalis strain Balt 44 and most numerous in those of strain JH162A of this species. In Tritrichomonas foetus strain KV-1 the number of IMPs in the EF was close to but somewhat lower than that in the mild strain of the human urogenital trichomonad. In both species, the anterior, but not the recurrent, flagella had rosette-like formations, consisting of ∼9 to 12 IMPs on both the PFs and EFs. The numbers and distribution of the rosettes appeared to vary among different flagella and in different areas of individual flagella of a single organism belonging to either species. The freeze-fracture electron micrographs provided a more complete understanding of the fine structure of undulating membranes of Trichomonadinae, as represented by Trichomonas vaginalis, and of Tritrichomonadinae (the Tritrichomonas augusta-type), as exemplified by Tritrichomonas foetus, than was gained from previous transmission and scanning electron microscope studies. Typically three longitudinal rows of IMPs on the PF of the recurrent flagellum of Trichomonas vaginalis were noted in the area of attachment of this flagellum to the undulating membrane. The functional aspects of the various structures and differences between certain organelles revealed in the two trichomonad species by the freeze-fracture method are discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 9 (1962), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. By means of electron microscopy, a study has been made of the fine structure of the macrogametocytes, microgametocytes and oocysts of Eimeria perforans from the intestine of the wild rabbit (Oryctolagus cuniculus). The parasites lie in a vacuole within the host cell. The surface of the gametocytes is not plain, but displays irregular protrusions. A large intranuclear body can be detected within the macrogametocytes. Similar structures are also found within the cytoplasm. Within the latter there exists a large spread out reticulum, the channels and vesicles of which concentrate especially close to the nuclear membrane. Tubuli are seen in the numerous mitochondria, which often have a dumb-bell shape.In most of the gametocytes irregular, strongly osmiophilic lipid inclusions are observed, which always are surrounded by the endoplasmic reticulum. Strange folded ovoid bodies are found within the cytoplasm of the oocysts. Nothing can be told with certainty of their nature and function. Probably they represent specific storage bodies.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Naturwissenschaften 41 (1954), S. 40-40 
    ISSN: 1432-1904
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Allgemeine Naturwissenschaft
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 61 (1963), S. 214-219 
    ISSN: 1432-0878
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The surface of the gametocytes and gametes of Eimeria perforans reveals tube-like extrusions which have not been discovered so far in coccidia. These slender tubes are 650 Å in width and at least 1,3μ in length. Probably they represent resorbing organelles. The tubes occur only at the surface of older female gametocytes and gametes and have not been observed in merozoites, schizonts, microgametocytes and male gametes. In transversal sections the tubes look like vesicles and are bordered by a membrane the layers of which are not sharply defined. The interior of the tubes seems to be empty after electron microscope observations. In longitudinal sections the membrane of the tubes is striated. The repeating unit of the dark and light bands amounts to about 165 Å. This appearance cannot be explained so far.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    ISSN: 1432-1955
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Parasitology research 24 (1964), S. 546-560 
    ISSN: 1432-1955
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Parasitology research 40 (1972), S. 165-176 
    ISSN: 1432-1955
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung An Cystenstadien von Besnoitia jellisoni wurden cytochemische Nachweisreaktionen unternommen, die als Ziel den ultrastrukturellen Nachweis von saurer Phosphatase und Polysacchariden hatten. Saure Phosphatase wurde in den Zoiten innerhalb der Mitochondrien, im perinukleären Raum, im endoplasmatischen Retikulum, innerhalb von Vakuolen und in geringem Maße auch im Golgi-Apparat dargestellt. In der Cystenwandung wurde das Enzym in den Mitochondrien, im endoplasmatischen Retikulum und im Golgi-Apparat des Wirtszellcytoplasmas angetroffen, das die innere Cystenschicht aufbaut. Die Polysaccharidgrana wurden nach der Methode von Thièry (1967) kontrastiert. Sie waren nie von einer Membran begrenzt und lagen meist frei im Cytoplasma. In einigen Fällen fanden wir sie jedoch auch einzeln oder zu mehreren in Vakuolen. Die Tatsache, daß sich innerhalb der Vakuolen auch sehr häufig Fraktionen derartiger Grana beobachten ließen, deutet auf einen dort verlaufenden Auf- oder Abbauprozeß hin. Nach Behandlung mit α- und β-Amylase wurden diese Grana herausgelöst; die Thièry-Reaktion verlief dann negativ.
    Kurzfassung: Résumé L'étude de la présence de phosphatase acide et de granules polysaccharidiques a été effectuée dans les formations kystiques de Besnoitia jellisoni (Frenkel, 1953), Protozoaire parasite de la souris. Dans la paroi kystique, la phosphatase acide apparait au niveau des mitochondries, des saccules ergastoplasmiques et de l'appareil de Golgi de la cellulehôte qui constitue l'enveloppe interne. Dans les endodyocytes, la phosphatase acide a été observée dans le reticulum endoplasmique, dans la cavité périnucléaire, dans les mitochondries, du côté interne des membranes vacuolaires et au niveau de l'appareil de Golgi. La réaction a été négative au niveau des rhoptries et des micronèmes. Dans l'enveloppe kystique, la réaction de Thièry est positive au niveau de nombreux petits amas de fines granulations de nature polysaccharidique disseminées dans le cytoplasme de la cellule-hôte. Dans les endodyocytes, le protéinate d'argent colore de nombreux granules ovoides, généralement libre dans le cytoplasme. Certains de ces grains polysaccharidiques sont envacuolés. Après action de l'α-amylase ou de la β-amylase, les grains de polysaccharides sont digérés. La réaction de Thièry est également positive au niveau de la membrane cellulaire des endodyocytes.
    Notizen: Summary The distribution of acid phosphatase and polysaccharide was investigated at the ultrastructural level in the cyst stage (zoite) of Besnoitia jellisoni. Acid phosphatase occurs in endoplasmic reticulum, perinuclear space, mitochondria, and vacuoles, which are probably food vacuoles. Some slight deposits are also seen in the Golgi-apparatus. In the inner part of the cyst-wall, which is formed by host cell cytoplasm, acid phosphatase was found in the Golgi-apparatus, in the endoplasmic reticulum, and in the mitochondria. The polysaccharide granules stained after the method of Thièry (1967) were always found without a limiting membrane. Normally they were observed free in the cytoplasm. Yet, in some cases they were found within vacuoles limited by a unit membrane. In these vacuoles often fractions of polysaccharide granules were seen. These observations indicate that within these vacuoles a process of fragmentation may take place. After treatment with α-amylase and β-amylase the polysaccharide granules disappeared and the Thièry-reaction was negative.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Parasitology research 40 (1972), S. 281-294 
    ISSN: 1432-1955
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Merozoiten des Coccids Eimeria falciformis aus der Hausmaus (Mus musculus) wurden elektronenmikroskopisch untersucht. Dabei wurden 26 Mikrotubuli beobachtet, die in den meisten Fällen regelmäßig dicht unterhalb der typisch strukturierten Pellikula angeordnet waren und vom vorderen zum hinteren Polring verliefen. In einigen Fällen war jedoch die regelmäßige Anordnung der röhrenförmigen Elemente nicht vorhanden, offenbar in Merozoiten, die gerade während der Fixierung eine Knickbewegung durchgeführt hatten. Dann lagen die Mikrotubuli in Zweier-, Dreier- oder Vierergruppen tiefer im Cytoplasma. Wie auf Längsschnitten zu erkennen war, verliefen sie nämlich, die Knickfalten der Merozoiten vermeidend, tiefer in Cytoplasma zwischen den beiden Zellpolen. Dieser Befund deutet auf eine mögliche Kontraktilität der subpellikulären Mikrotubuli und ihre Beteiligung an Bewegungsvorgängen hin. Neben diesen meistens unter der Pellikula gelegenen Mikrotubuli konnten ferner ganz ähnlich strukturierte Elemente in großer Zahl unregelmäßig im Cytoplasma verteilt bei einigen Merozoiten angetroffen werden.
    Notizen: Summary The merozoites of Eimeria falciformis from the mouse were investigated with the electron microscope. Twenty-six microtubules were observed; these were in most cases regularly arranged just beneath the typical pellicle and extended from the anterior to the posterior polar ring. In a few specimens which were in the process of a flexing movement during fixation, the microtubules were located deep in the cytoplasm in groups of 2, 3 or 4. In longitudinal sections it was seen that such groups of microtubules were arranged so as to avoid the infolded area of the pellicle. This finding indicates the possibility that the subpellicular microtubules are contractile and participate in the flexing movement of the merozoite. In addition to these microtubules, which were usually lying next to the pellicle, numerous elements having a similar structure were distributed irregularly in the cytoplasm of some merozoites.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Parasitology research 69 (1983), S. 823-826 
    ISSN: 1432-1955
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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